Car door



Jan. 14, 1936. K. J. ToBlN ET AL CAR DOOR Filed May 20, 1933 4 sheets-sheet 1 ma. |0|| :uw @Y Ihn A@ @Irl llw l. i 1:15.@

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Jan. 14, 1936. K, 1. ToBlN Er AL CAR DOOR Filed May 20, 1953 4 Sheets-Sheet 2 anx Jan. 14, 1936.

K. .1. TBIN ET AL. 2,027,566

CAR DOOR Filed May 2o, 1935 4 Sheets-Sheet 3 fi//VENTo/es- KENNETH J 755m/ #fom/@LD MHDLHA/o @TTY Jan. 14, 1936. K. J. TOBIN ET AL CAR DOOR Filed May 20, 1953 4 Sheets-Sheet 4 -/A/VEA/Tofwy KENNETH J 7e//v 77-/oeVs/.D MHD/.HND @YN M @TTY Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE CAR DOOR land, Ohio, a corporation of Ohio Application May 20, 1933, Serial No. 671,972

26 Claims.

This invention relates to doors and concerns itself primarily with sliding doors for railway house cars.

It is an object of this invention to provide sliding doors which shall be frictionally supported in closed position and capable of unimpeded movement between closed and full open positions to fully expose the door opening controlled by said door.

A further object is to provide sliding car doors capable of support by antifriction means having relative movement with respect to said doors upon tracks for uninterrupted movement to full open and closed positions, the tracks having indentures adapted to receive the antifriction. means in the closed position of the door, whereby the door is frictionally supported upon said tracks.

A further object is to provide sliding car doors frictionally supported in closed position upon tracks having indentures for receiving relatively movable antifriction means for the doors, said doors being constructed whereby the initial opening movement thereof will urge the anti- 25 friction means out of the indentures and into door supporting position upon said tracks.

A further object is to provide sliding car doors frictionally supported in closed and full open positions upon tracks having indentures for receiving relatively movable antifriction supporting means for the doors, said doors being constructed whereby the initial opening and closing movements thereof will urge the antifriction means out of the indentures and into door supporting position upon said tracks, said doors in full open position completely exposing the door openings controlled thereby.

A further object is to provide sliding car doors frictionally supported in closed and full open 4), lpositions upon tracks and capable of travel betweenl said positions upon relatively movable vantifriction means, said doors carrying levers adapted toimpart movement to said means to effect release of the frictional engagement and to dispose the doors upon and in peripheral engagement with said means.

A further object is to provide sliding doors fricticnally supported in closed and full open positions upon tracks, the doors comprising Ri members adapted to have peripheral engagement upon relatively movable spaced balls durg ing travel between said positions, said doors carrying levers adapted to extend through said members and exert a thrust upon a ball spacer `for imparting movement to the balls to eilect REISSUED (Cl. 20-22) OCT t 7 193g release of the frictional engagement and to dispose the doors upon the balls.

Other objects of the invention will become clear as the description thereof proceeds.

In the drawings forming part of this specification Figure 1 is a fragmentary elevation of a sliding car door embodying one form of the invention, the door being illustrated in closed position;

Figure 2 is a view similar to Figure 1, showing the door in full open position;

Figure 3 is a fragmentary elevation of a. sliding car door embodying another form of the invention;

Figure 4 is a vertical section on an enlarged scale taken on line 4-4 of Figure 1;

Figure 5 is a partial vertical section taken on line 5-5 of Figure 4;

Figure 6 is a vertical section on an enlarged scale taken on line 6 6 of Figure 3;

Figure 7 is a vertical section taken on line 1-1 of Figure 6;

Figure 8 is a fragmentary elevation of a sliding car door embodying a further form of the invention, the door being illustrated in closed position;

Figure 9 is a view similar to Figure 8 illustrating the door in full open position;

Figure 10 is a vertical section on an enlarged scale taken on line Ill-Ill of Figure 8;

Figure 11 is a partial elevation illustrating a sliding car door embodying another form of the invention, the door being shown in closed position;

Figure 12 is a view similar to Figure 11, showing the door in full open position; and

Figure 13 is a vertical section on an enlarged scale taken on line I3-I3 of Figure 11.

Referring to the drawings and to the form oi' the invention illustrated in Figures l, 2, 4 and 5, there is shown a portion of a side wall designated by the numeral I0 of a railway house car. Said side wall is provided with a door opening II defined in part by the front door post I2, the rear door post I3 and the oor I4. The door opening II is adapted to be closed by means o! a sliding door I5 which, as illustrated, is preferably constructed of metal and may include the horizontal corrugations I6 which at their ends` merge into vertical corrugations I1 and I8 situated inwardly of the vertical edges of the door. The door is adapted to be maintained upon the` car side by means of a track I9 situated below the 1001' opening and carried upon the car in any desired manner. In its closed position the door is adapted to be locked by means of the mechanism indicated generally by the reference numeral 20. An opening and closing arrangement. designated as a whole by the reference numeral 2|, may be utilized to impart initial opening movement and final closing movement to the door.

To facilitate movement of the door upon the tracksbetween closed and full open positions a plurality of antifriction means preferably in the form of balls 22 may be utilized. These balls are disposed uponl the track and are adapted to support the door during its travel by engagement with shoulders 23 and 24 provided on the member 25 secured to the lower horizontal margin of the door. It will be apparent that during the travel of the door upon the track the balls 22 will have relative movement with respect to the track and to the door. It is desirable that the balls be maintained in definite spaced relationship vin order to properly support the door and for this purpose a ball spacer 26 is utilized.

With reference to Figure 1 of the drawings it will be apparent that the door in its closed position is disposed upon the track so as to have frictional engagement therewith. To this end the track I9 is provided with indentures 21 and 28. In the closed position of the door, as shown in Figure 1 of the drawings, these indentures are adapted to receive the balls 22 whereby the door may come into frictional engagement with the track.

In view of the relatively movable association between the balls 22 and the door and track itis\ preferred to provide a mechanism to insure disposition of said balls upon the track for supporting relationship to thedoor. A pivoted hook member 29 is carried by the member 25. In the closed position of the door, as best illustrated in Figure 5 of the drawings, the hook member 29 has interengagement with an upstanding lug 30 provided on the ball spacer 26. It is to be observed from Figures 1 and 5 that the spacer 26 comprises preferably end portions 3| and 32 adapted to be supported upon the balls 22.

The engagement between the hook member 29 and the upstanding lug 30 occurs in the closed position of the door when said door is frictionally supported upon the track and the balls 22 are, consequently, received within the track indentures 21 and 28. In order to move the door to open position the opening and closing mechanism 2| is actuated and the door moved along the track. Inasmuch as the hook member 29 is carried by the door it will move with the door relative to the track and exert a pull upon the ball spacer 26 through its engagement with the lug 30 so as to impart corresponding movement to the balls 22. The balls and spacer are readily movable since the balls are free of the weight ofv the door which at this time is carried by the track. In this initial opening movement of the door certain of the balls will move upwardly by virtue of the inclined portions A and B of the indentures until they are engaged by the shoulders 23 and 24 formed on member 25. At this point in the initial opening movement of the door the balls are still in the indentures and. in engagement with the member 25 while the door is frictionally supported upon the track. The door then, by its continued movement, imparts movement to the rollers to which the support of the door is transferred as the rollers continue their upwardl movement out of the indentures. The remainder of the opening movement of the door may then easily be accomplished. During the 4initial part of the antifrictional movement of the door the hook member 29 will be .disengaged from the lug 30, this disengagement being aided by the taper provided on the engaging faces of the hook and the lug. From the nature of the support of the door upon the balls which now carry the weight of the door it will be apparent that the door and, hence, the hook member 29 will travel faster than the balls and, consequently, faster than the ball spacer which carries the lug 30. This difference in the speed of travel of the hook and the lug will eil'ect release ofthe hook from the lug, the tapered faces on these members assisting such release. During movement of the door to closed position the hook member 29 will overtake the lug 30 which will cause said member to swing about its pivot and fall into engagement with said lug.

It is desirable that the door in its movement between closed and full open positions have unimpeded movement. This feature is obtained in the instant embodiment of the invention by utilization of a pair of balls disposed. substantially centrally of the door when the latter is in its closed position and one ball positioned adjacent the rear vertical edge of the door. It will be noted that the indenture 28 is of such size as to receive the single ball whereas the indenture 21 is capable of receiving the pair of balls..

In the movement of the door to its full open position the pair of balls 22 travel over that portion of the track provided with the indenture 28.

It will be apparent, however, that when either of the pair of balls is positioned in or above the indenture 28 the other of said balls will be upon l the track in eiective relationship with the vdoor to support the latter so that the indenture 23 does not interfere with the uninterrupted movement of the door. Similarly, the door in its closing movement will have smooth unimpeded movement.

A somewhat modified form of the invention is illustrated in Figures 3, 6 and 7 of the drawings. A ball spacer 33 utilized in this form of. the invention tp properly space the balls 22 is supported by the track rather than by the balls. in View of this mode of support of the ball spacer the pivoted hook member 29 may be dispensed with and in its place a rigid hook member 34, formed preferably as an integral portion of the corner casting 35, may be utilized. As illustrated in Figure '1 of the drawings the hook member 34 is adapted to have interengagement with an upstanding lug 36 provided on the ball spacer 33.

It will be manifest that movement of the door from its closed position toward open'position will, by the engagement between the hook member 34 and the lug 36, impart corresponding movement to the spacer 33 and the balls 22 in o'rder to cause said balls to move upwardly into engagement with said door. Continued movement of said door will effect movement of said balls and transference of the support of the door from the track to the balls, the latter thus rising out of the indentures and being disposed upon the track with the doorresting upon the balls. In view of the fact that the spacer is supported upon the track elevation of the door will eiect disengagement between the hook member 34 and the lug 36 so that the door may then be moved to its full open position. It will be clear with- `the rear ball will be received within the track out further description that the door embodying the instant form of the invention will also have uninterrupted movement between closed and full open positions.

in the former embodiments of the invention the doors in their full open position are disposed upon the balls. In the embodiment of the invention illustrated in Figures 8, 9 and l0, however, the door is supported frictionally upon the track not only in the closed position thereof but in the full open position as well. As in the form of the invention described immediately above a Z shaped member 31 is secured to the lower horizontal margin of the door. This member is disposed with its web 38 extending outwardly from the door and lying in a substantially horizontal plane. The flanges 39 and 40 of said member extend vertically in opposite directions, the member being secured to the door as by means of rivets 4I extending through the vertical flange 40. The ends of the Z shaped member 31 are adapted to be closed by corner castings 42 and 43. An angle member 44 is secured to the underside of the web of the Z-bar 31 and one leg 45 thereof is adapted to extend downwardly between the car and the track I9 so as to prevent disengagement of the lower portion of the door from the track by outward movement of the door and to provide, together with the vertical ange 39 of the Z-bar 31, a longitudinally extending pocket for the reception of the supporting balls 22. A channel member 46 is secured to the Z shaped member 31 so that the flanges 41 and 48 thereof extend downwardly into peripheral engagement with the balls 22. The channel member 46 is preferably continuous between the castings 42 and 43 and is deformed at its ends. These deformations preferably take the form of inclined copes 49 and 5U. The track I9 is provided with an indenture 5| positioned intermediate the vertical edges of the door when said door is in closed position and with an indenture 52 positioned intermediate the vertical edges of the door when the door is in full open position.

The door is shown in its closed position in Figure 8 of the drawings. In this position the forward ball 22 is disposed within the track indenture 5| and the rear ball is disposed adjacent to the inclined portion 56 of the channel member 46. With this disposition of the parts referred to the door is in frictional engagement with the track. To move the door to open position the opening and closing arrangement 2| illustrated in Figure 1 of the drawings may be utilized to impart initial opening movement to lthe door. 'I'his initial movement of the door will in turn impart movement to the balls which act substantially simultaneously, because of the ball spacer 53. 'Ihe inclined portion at the rear end of the channel member 46 will facilitate upward movement of the door and disposition of the anges 41 and 48 of the channel member upon the balls. 'I'he forward rolling movement of the rear ball will, through the agency of the spacer, impart movement to the forward ball so as to urge said ball out of the track indenture 5I and into corresponding peripheral engagement with the flanges 41 and 48 of the channel member. When the door has been disposed upon the balls said door may readily be moved to the full open position shown in Figure 9 of the drawings. In this position of the door the forward ball will lie adjacent the inclined portion at the forward end of the channel member 46 while indenture 52 so that the door may be frictionally supported upon the track. It will be manifest that by the construction of the channel member 46 at the ends thereof and the relationship thereof with the track indentures 5I and 52 free movement of the door will be had without impedance by the track indentures.

To impart initial closing movement to the door the mechanism shown in Figure 9 of the drawings may be utilized. This mechanism comprises a lever 54 pivoted intermediatey its ends as indicated at 55 upon a door stop 56 which may be secured to the track I9. The lever 54 is provided with a cam portion 51 lying in the path of opening movement of the door.

As the door. approaches its full open position it will engage the cam portion 51 and swing the lever 54 into the position shown in Figure 9 of the drawings where it is ready for actuation to move the door toward closed position. A lug 58 adapted to engage a shoulder 59 provided on the door stop 56 maintains. the lever 54 in such position that the action of the door will dispose the lever as illustrated. It will be observed from Figure 9 of the drawings that while the door of the instant embodiment of the invention is in its full open position the door opening ll is completely exposed.

A further form of the invention in which the door is frictionally supported upon the track in closed and full open positions is illustrated in Figures l1, 12 and 13 of the drawings.v As in the two foregoing embodiments the door cornprises the Z shaped member 31 secured to the lower horizontal margin of the door, the angle member 44 secured to said Z shaped member and.

the channel member 46, the depending anges cf which are adapted to be disposed in peripheral engagement with the balls 22. While the channel member 46 may be a continuous member as in the previous embodiment of the invention it is preferred that separate members be utilized, each of said members being provided with inclined ends 49 and 59. A lever 60 pivotally supported upon a bracket 6I secured to the door extends through an opening 62 formed in the Z-bar 31 and angle member 44 intermediate the adjacent ends of the channel members 46. This end of the lever 60 may be bifurcated as indicated at 63 so as to straddle a portion of the spacer 64 which maintains the supporting balls 22 in spaced relationship and engage another portion of said spacer in order to impart movement thereto and to said balls. In this form of the invention it is to be observed that the track 65 is not provided Withvany indentures.

To move the door from its closed position shown in Figure l1 of the drawings' the lever 60 is grasped and swung in a clockwise direc'- tion. The swinging movement of the lever imparts a thrust upon the ball spacer which in turn forces the balls from their position adjacent the inclined ends 5Fl of the channel mem-1 bers 46 to peripheral engagement with the flanges of said channel so as to release the frictional engagement of the door and the track and to dispose said door upon the balls. The door may then be moved to the full closed position illustrated in Figure 12 of the drawings in order to completely expose the door opening. As shown in this figure of the drawings the balls y have now assumed a position adjacent the inclined ends 49 of the channel members 46 and the door is again supported frictionally upon.

the track. To move the door to its closed position again the lever 60 is swung in a counterclockwise direction in order to dispose the door upon the balls 22 so that the door may be moved easily to said position. It will be observed that the movement of the door between closed and full open positions is unimpeded and that in said positions the door is irictionally supported upon the track.

It is apparent that numerous changes and modifications in the details of the invention will be clear to those skilled in the art. It is intended. therefore, that all such modifications and changes be comprehended within this in vention, which is to be limited only bythe scope of the claims appended hereto.

1. In combination, a door having the normal width corresponding to the door opening controlled by said door, arunway provided on said door, the length of said runway being not greater than the width of said door, a track, spaced rolling means disposed uponsaid track for longitudinal movement relative to said door and track and adapted to engage said runway and support said door for movement upon said track, said door being irictionally supported upon said track in closed position and capable of unimpeded movement upon said rolling means to full open position to completely expose the door opening controlled by said door.

2. In combination, a door having the normal width corresponding to the door opening controlled by said door, a'runway provided on said door, the length of saidy runway being not greater than the width of said door, a track, spaced rolling means disposed upon said track for longitudinal movement relative to said door and track and adapted to engage said runway and support said door for movement upon said track, spaced indentures provided in said track adapted to receive said rolling means in the closed position of said door whereby said door is irictionally supported by said track, said door being capable of uninterrupted movement upon 'said rolling means to i'ull open position to completely expose the door opening controlled by said door:

3. In a railway house car having a door opening, a door, a track, spaced rolling means disposed upon said track capable ot longitudinal movement'relative to said door for supporting said door for movement upon said track, spaced indentures providedin said track adapted to receive said rolling means in the closed position of said door whereby said door is irictionally supported by said track, the rearwardly positioned indenture being adapted to receive the rearwardly disposed rolling means but being incapable of receiving the forwardly disposed rolling means whereby said door may have unimpeded movement upon said track to full open position to completely expose vsaid door opening.

4. In a railway house car having a door opening, a doora track, spaced rolling means disposed upon said track. capable of movement relative to' said door ior supporting said door` for movement upon said track, said rolling means comprising a pair of balls remote from the' rear edge of said door and a ball adjacent to said edge, spaced indentures provided in said track adapted to receive said balls in the closed position of said door whereby said door is frictionally supported by said track, the rearwardly positioned indenture being adapted to receive said one ball but being incapable of receiving said pair of balls whereby said door may have unimpeded movement upon said track to full open position to completely expose said door Opening. s

5. In combination, a door, a track, spaced rolling means disposed upon said track for longitudinal movement relative to said door rand adapted to support said door for movement upon said track, a spacer movable with and maintaining said rolling means in spaced relation, said door being irictionally supported upon said track in closed position,'means engaging said spacer and responsive tc the opening movement of said door for disposing said rolling means in door engaging position, said door being capable of unimpeded travel upon said rolling means to full open position to completely expose the door opening controlled by said door.

6. In a railway house car having a door opening, a door, a track, spaced rolling means disposed incapable o! receiving the forwardly disposed rolling means whereby said door may have unimpeded movement upon said track to full open position to completely expose said door opening, and means responsive to the opening movement of said door for moving said rolling means relative to said indentures and into door engaging position.

'1. In combination, a door, a track, spaced rolling means disposed upon said track and movable longitudinally relative to said door for supporting said door for movement upon said track, a spacer movable with and maintaining said rolling means in spaced relation, spaced indentures provided in said track adapted to receive said rolling means in the closed 'position of said door whereby said door is frictionally supported upon said track and means carried by said door having engagement with said spacer and operative in the opening movement of said door for imparting movement to said spacer and rolling means for moving said balls relative to said indentures and'into door engaging position, said door having unimpeded movement upon said rolling means to lull open position to completely expose the door opening controlled by said door.

8. In combination, a door, a track, spaced rolling means" disposed upon said track and movable longitudinally relative to said door for supporting said door for movement upon said track, a spacer carried by and maintaining said rolling means in spaced relation, spaced indentures provided in said track adapted to receive said rolling means in the closed position of said door whereby said door is irictionally supported upon said track and means pivotally carried by said door having engagement `with said spacer and operative in the opening movement of said door for imparting movement to said spacer and rolling means for moving said balls relative to said indentures and into door engaging position,

anime 5 9. -In combination, a door, a track, spaced rolling means disposed upon said track and movable longitudinally relative to said door for supporting said door for movement upon said track, a spacer disposed upon said track and maintaining said rolling means in spaced relation, spaced indentures provided in said track adapted to receive said rolling means in the closed position of said door whereby said dooris frictionally supported upon said track and means carried by said door having engagement with said spacer and operative in the opening movement of said door for imparting movement to said spacer and rolling means for moving said balls relative to said indentures and into door engaging position, said door having unimpeded movement upon said rolling means to full open position to completely' expose the door opening controlled by said door.

10. In a railway freight car having a door opening, a door therefor, a track, rolling means supporti-ng said door for movement upon said track, said door being frictionally supported upon said track in full open position and means pivotally supported upon said car adapted to dispose said door upon said rolling means for movement to closed position, said means being actuated to operative position by said door in the opening movement thereof;

1l. In a railway freight car having a door opening, a door therefor, a longitudinally extending member secured to a horizontal margin of said door, a track member, spaced rolling means having peripheral engagement with said members for supporting said,door for movement upon said car, said longitudinally extending member being deformed adjacent the ends thereof, said track member being deformed at spaced points intermediate the vertical edges of said door in'the closed position and in the full open position thereof, said rolling means being received in certain of said deformations in the closed position of said door and in the other of said deformations in the full open position of said door for the purpose set forth.

12: In a railway freight car having a door opening, a door therefor, a longitudinally extending member secured to a horizontal margiri of said door, a track member, spaced rolling means having peripheral engagement with said members for supporting said door for movement upon said car, said longitudinally extending member being deformed adjacent the ends thereof, to provide portions inclined upwardly toward the front and rear vertical edges of said door, respectively, said track member having indentures at spaced points intermediate the vertical edges of said door in the closed position and in the full open position thereof, said rolling means being received in one of the deformed ends adjacent to an inclined portion and in one of said indentures in the closed position of the door and in the other deformed end adjacent to the other inclined portion and the other indenture in the full open position of said door for the purpose set forth.

13. In a railway freight car having a door opening, a door therefor, a longitudinally extending member secured to a horizontal margin of said door, a track member, spaced rolling means having peripheral engagement with said members for supporting said door for movement upon said car, a spacer for maintaining said rolling means in spaced relation, said longitudinally extending member being deformed adjacent the ends thereof to provide portions inclined upwardly toward the front and rear vertical edges of said door, respectively, said track member having indentures at spaced points intermediate the vertical edges of said door in the closed position and in the full open position thereof, said rolling means being received in one of the deformed ends adjacent to an inclined portion and in one 'of said indentures in the closed position of the door and in the other deformed end adjacent to the other inclined portion and the other indenture in the full open position of said door for the purpose set forth.

14. In a railway house car having a door opening, a door therefor, a track, spaced rolling means having peripheral engagement with said door and said track for supporting said door for movement upon said car, a spacer for maintaining said rolling means in spaced relation, said door being deformed adjacent to the vertical edges thereof and intermediate said edges, said rolling means being received in said deformations in full open and closed positions of said door whereby the latter is frictionally supported upon said track and means for disposing said rolling means in supporting relationship with said door.

15. In a railway house car having a door opening, a door therefor, a track, spaced rolling means having peripheral engagement with said door and said track for supporting said door 4for movement upon said car, a spacer for maintaining said rolling means in spaced relation, saidvdoor being deformed adjacent to the vertical edges thereof and intermediate said edges, said rolling means being received in said deformations in full open and closed positions of said door, whereby the latter is frictionally supported upon said track and a lever pivotally carried by said door for actuating saidspacer to dispose said rolling means in supporting relationship with said door.

16. In a railway housecar having a door opening, a door therefor, spaced members presenting downwardly disposed iianges secured to a horizontal margin of said door, the remote ends of said members being spaced inwardly from the vertical edges of said door, a track, spaced balls having peripheral engagement with said flanges and said track for supporting `said door for movement upon said car, a spacer for maintaining said balls in spaced relation, said balls being received in the appropriate pockets provided by the spacing of said members in full open andV closed positions of said door whereby the latter is frictionally supported upon said track and lever means for actuating said spacer to dispose said balls in supporting relationship with said door.

17. In combination, a door, a track, spaced rolling means disposed upon said track and movable longitudinally relative to said door for supporting said door for movement upon said track, a spacer .movable with and maintaining said rolling means in spaced relation, spaced indentures provided in said ,track adapted to receive said rolling means in the closed position of said door whereby said door is frictionally supported upon said track, said door being provided with means disposed in engagement with said spacer when said rolling means are in said indentures, said means in the initial opening movement of said door imparting movement to said spacer and rolling means for moving said rolling means out of said indentures andl into door supporting position.

18. In combination, a door, a track, spaced rolling means disposed upon said track for longitudinal movement relative to said door and adapted to support said door for movement upon said track, said door being frictionally supported upon said track in closed position, and means operatively connecting said door and said rolling means in the closed position of said door, whereby said door in its initial opening movement will impart movement to said rolling means to dispose the same in door supporting position.

19. In combination, a door, a track, spaced rolling means disposed upon said track for longitudinal movement relative to said door and adapted to support said door for movement upon said track, said door being frictionally supported upon said track in closed position, and means operatively connecting said door and said rolling means in the closed position of said door, whereby said door in its initial opening movement will impart movement to said rolling means to dispose the same in door supporting position, said connecting means being auto matically disengaged during said initial movement of the door for the purpose set forth.

20. In combination, a door, a track, spaced rolling means disposed upon said track for longitudinal movement relative to said door and adapted to support said door for movement upon said track, said door being frictionally supported upon said track in closed position, and means operatively connecting said door and said rolling means in the closed position of said door, whereby said door in its initial opening movement will impart movement to said rolling means to dispose the same in door supporting position, said connecting means being automatically disengaged during said initial movement of the door and being automatically engaged during the final closing movement of said door for the purpose set forth.

21. In combination, a door, a track, spaced balls disposed upon said track for longitudinal movement relative to said `door and adapted to support said door for travel upon said track, spaced indentures provided in said track adapted to receive said balls in the closed position of said door whereby said door is frictionally supported by said track, and means operatively connecting said door and said balls in the closed position of said door, whereby said door in its initial opening movement will impart movement to said balls out of said indentures to dispose the same in door supporting position.

22. In combination, a door, a track, spaced balls disposed upon said track for longitudinal movement relative to said door and adapted to support said door for travel upon said track, spaced indentures provided in said track adapted to receive said balls in the closed position of said door whereby said door is frictionally supported by said track, and means operatively connecting said door and said balls in the closed position of said door, whereby said door in its initial opening movement will impart movement to said balls out of said indentures to dispose the same in door supporting position, said connecting means being automatically disengaged during said initial movement of said door.

23. In combination, a door, a track, spaced balls disposed upon said track for longitudinal movement relative to said door and adapted to support said door for travel upon said track, spaced indentures provided in said track adapted to receive said balls in the closed position of said door whereby said door is frictionally supported by said track, and means operatively connecting said door and said balls in the closed position of said door, whereby said door in its initial opening movement will impart movement to said balls out of said indentures to dispose the same in door supporting position, said connecting means being automatically disengaged during said initial movement of said door, and being automatically engaged during the final closing movement of said door for the purpose set forth.

24. In combination, a door, a track, spaced rolling means disposed upon said track and movable longitudinally relative to said door for supporting said door for movement upon said track, a spacer movable with and maintaining said rolling means in spaced relation, spaced indentures provided in said track adapted to receive said rolling means in the closed position of said door whereby said door is frictionally supported upon said track, said door being provided with means disposed in engagement with said spacer when said rolling means are in said indentures, said means in the initial opening movement of said door imparting movement to said spacer and rolling means for moving said rolling means out of said indentures and into door supporting position, said 3 spacer engaging means being automatically released from said spacer during the initial opening movement of said door.

25. In a railway freight car having a`door opening, a door therefor having the normal width corresponding to the door opening controlled by said door, a track, spaced rolling means having peripheral rolling engagement with said door and said track for supporting said door upon said track during the travel thereof, said rolling means beingv disposed intermediate the vertical edges of said door during the full movement of said door, said door and said track being deformed, said rolling means being received in said deformations in the closed and full open positions of said door, whereby said door is frictionally supported upon said track in said positions, said deformations and rolling means having association whereby said door will have uninterrupted movement upon said rolling means to full open position to fully expose said door opening.

26. In combination, a door, a track, spaced rolling means disposed upon said track for longitudinal movement relative to said door and adapted to support said door for movement upon said track, a spacer movable with and maintaining said rolling means in spaced relation, said door being frictionally supported upon said track in closed position, means engaging said spacer and responsive to the opening movement of said door for disposing said rolling means in door engaging position, said door being capable of antifrctional movement upon said rolling means.

KENNETH J. TOBIN. THORVALD MADLAND. 

